NOT A CHIMP

NOT A CHIMP
Click on the cover to link to OUP's e-catalogue then turn to the biology section.

Interview Podcast with George Miller

Interview Podcast with George Miller
Click on the pic to link to the NOT A CHIMP podcast on Blackwell's Website

Preface to "Not A Chimp: The Hunt For The Genes That Make Us Human"

In many ways, this book is born out of frustration for a professional career in popular science television where ideas about comparative primate cognition, and the similarities and differences between us and our primate relatives, have continually circled me but constantly evaded my grasp in terms of the opportunity to transform them into science documentary. On the plus side, keeping a watching brief for over a quarter of a century on subjects like comparative animal cognition and evolution allows you to watch a great deal of water flow under the bridge. Fashions come and fashions go - specifically, perspectives on the similarity - or otherwise - of human and ape minds.

I remember the first Horizon science documentary about the chimpanzee Washoe, the great ape communicator, using American Sign Language to bridge the species barrier. And, later, Kanzi the bonobo jabbing his lexicon. These were the apes, as Sue Savage-Rumbaugh has put it, that were "on the brink of the human mind".

I remember when the pre-print of Machiavellian Intelligence, by Andrew Whiten and Dick Byrne, plopped onto the doormat of the BBC Antenna science series office in 1988. Suddenly primatology had become a great deal more exciting. Could primates, and especially higher primates like chimpanzees, really be as full of guile, as dastardly, as cunning, and as manipulative as the eponymous Florentine politician? Could they really reach deep into the minds of other individuals to see what they believed and what they wanted, and turn that information into deception?

I remember discussing primate cognition with a young Danny Povinelli, as we sat finger-feeding ourselves shrimp gumbo and new potatoes out of plastic Tupperware containers in a Lafayette restaurant surrounded by an alligator-infested moat, before returning to his kingdom - the New Iberia Research Centre - where the University of Louisiana had lured him back to his native deep South by turning a chimpanzee breeding centre for medical laboratory fodder into a primate cognition laboratory with one of the largest groups of captive chimpanzees in the country. He looked like a kid who had just been thrown the keys to the tuck shop.

In those days Povinelli shared the zeitgeist - spread by Whiten's and Byrne's work, and started by Nick Humphrey and Alison Jolly before them - that, since the most exacting and potentially treacherous environment faced by chimpanzees and other primates was not physical, but the social environment of their peers, they had evolved a form of social cognition very much like our own, in order to deal with it. This was further elaborated into a full-blown "social brain" hypothesis by Robin Dunbar, who related brain neocortex size to social group size throughout the primates and up to man. Povinelli's early work reflects this optimism for the mental life of apes, but both ape-language and ape-cognition research was subjected to a cold douche of searching criticism during the 1990s, and misgivings set in regarding the effectiveness of the experiments that had been constructed to guage ape cognition. Now the worm has turned again, with a number of research groups emerging with bolder and bolder claims for the Machiavellian machinations of primate minds, only to be powerfully countered by the curmudgeonly skepticism, chiefly by Povinelli, that these researchers are merely projecting their mental life onto that of their subjects; that, rather in the frustrating manner of Zeno's arrow that could never quite reach its target because it continually halved its distance to it, no experiment constructed thus far can actually get inside the mind of a chimp and show us exactly what it does and doesn't know, or how much, about the minds of others or the way the physical world works. One influential part of the world of comparative animal cognition talks of a continuum between ape and human minds and shrinks the cognitive distance between us and chimps to almost negligible proportions, while another returns us to the unfashionable idea that human cognition is unique, among the primates, after all.

When I began writing this book the working title was "The 1.6% that makes us human". My aim had always been to scrutinize the impression put about in the popular science media that humans and chimps differ by a mere 1.6% in our genetic code - or even less - and that it therefore makes complete sense that this minuscule genetic difference translates into equally small differences in cognition and behaviour between apes and man. However, contemporary genome science and technology, over the last few years, have dramatically advanced the power and resolution with which scientists can investigate genomes, eclipsing the earlier days of genomic investigation that gave rise to the "1.6% mantra".

As with comparative cognitive studies, conclusions on chimp-human similarity and difference in genome research depend crucially on perspective. To look at the complete set of human chromosomes, side by side with chimpanzee chromosomes, at the level of resolution of a powerful light microscope, for instance, is to be overwhelmed by the similarity between them. Overwhelmed with a sense of how close our kinship is with the other great apes. True, our chromosome 2 is a combination of two chimp chromosomes - giving humans a complement of 23 chromosome pairs to 24 in chimps, gorillas and orang-utans - but even here you can see exactly where the two chimp chromosomes have fused to produce one. The banding patterns you visualize by staining the chromosomes match up with astonishing similarity - and that banding similarity extends to many of the other chromosomes in the two genomes. However, look at a recent map of the chromosomes of chimps and humans, aligned side by side, produced by researchers who have mapped all inversions - end-on-end flips of large chunks of DNA - and the chromosomes are all but blotted out by a blizzard of red lines denoting inverted sequence. Now you become overwhelmed by how much structural change has occurred between the two genomes in just 6 million years. True, not all inversions result in changes in the working of genes - but many do - and inversions might even have been responsible for the initial divergence of chimp ancestor from human ancestor.

The extent to which you estimate the difference between chimp and human genomes depends entirely on where you look and how deeply. Modern genomics technology has led us deep into the mine that is the genome and has uncovered an extraordinary range of genetic mechanisms, many of which have one thing in common. They operate to promote variability - they amplify differences between individuals in one species. We now know, for instance, that each human is less genetically identical to anyone else than we thought only three years ago. When we compare human genomes to chimpanzee genomes these mechanisms magnify genetic distance still further. I have tried, in this book, to follow in the footsteps of these genome scientists as they dig deeper and deeper into the "Aladdin's Cave" of the genome. At times the going gets difficult. Scientists, like any explorers, are prone to taking wrong turnings, getting trapped in thickets, and covering hard ground, before breaking through into new insights. I hope that those of you who recoil from genetics with all the visceral horror with which many regard the sport of pot-holing will steel yourselves and follow me as far as I have dared to go into Aladdin's Cave. For only then will you see the riches within and begin to appreciate, as I have, just how limited popular accounts of human-chimpanzee genetic difference really are. Let me try and persuade you that this is a journey, if a little arduous at times, that is well worth taking.

There are a number of scientists around the world who have the breadth and the vision to have begun the task of rolling genetics, comparative animal cognition, and neuroscience into a comprehensive new approach to the study of human nature and this is part, at least, of their story. They strive to describe the nature of humans in terms of the extent to which we are genuinely different to chimpanzees and the other great apes. Somehow, over 6 million years, we humans evolved from something that probably resembled a chimpanzee (though we cannot yet be entirely sure) and the answer to our evolution has to lie in a growing number of structural changes in our genome, versus that of the chimpanzee, that have led to the evolution of a large number of genes that have, effectively, re-designed our brains and led to our advanced and peculiar human cognition.

If you don't believe me, hand this book to your nearest friendly chimpanzee and see what he makes of it!

Sunday, 29 August 2010

Why Hauser Did It

I have posted recently about the sad denouement of Marc Hauser, the Harvard psychology professor mentioned for his work on the evolution of morality in NOT A CHIMP, who has been found guilty by his university of mishandling data in his laboratory. Here is a fascinating essay by Derek Bickerton - famous for his work on language and the evolution of language - and his take on the sorry affair which chimes in perfectly with the sentiments and facts expressed both in NOT A CHIMP and in the complementary recent publication JUST ANOTHER APE? by Helene Guldberg.

Strange Tongue

Starting from language you can get to anywhere.
by Derek Bickerton

WHY HAUSER DID IT

Scientific dogma, not Hauser is to blame for misconduct
Published on August 19, 2010

Derek Bickerton is emeritus professor of linguistics at the University of Hawaii; his most recent book is Adam's Tongue: How humans made language, how language made humans (2009).

By now everyone's heard that Marc Hauser, Harvard Professor of Psychology, known for his work on cognition in monkeys and on the evolution of morality, has been under investigation by Harvard for scientific misconduct. And despite Harvard's stonewalling, an article in the Chronicle of Higher Education reveals that his misconduct went far beyond mere sloppy record-keeping.

At first, the whole affair seems baffling. You can understand why some over-ambitious post-doc or some aging and so-far-unsuccessful researcher might try to tweak Nature in order to achieve their dreams, But Hauser is a still relatively young yet already world-famous scientist who appeared to be at the top of his game. Why on earth would he do it?

The answer to that question turns out to be key in understanding the last half-century of the behavioral sciences and the forces that drove it. Hauser was simply a victim of those forces. And here's why.

For half a century, a major goal of the behavioral sciences has been to show that the differences between humans and other animals are in reality much less than they had seemed to previous generations. Two powerful forces combined to support that effort, one biological, one ideological. The biological force was the gradualness of evolution, which changed imperceptibly from a reasonable general rule into a dogma. If evolution happened always through a series of tiny steps, then there should not be any significant gaps between the abilities of related species. In light of this belief, the huge apparent gaps in language and cognition between humans and any other species constituted an acute embarrassment. If one could show that those gaps were only apparent, that embarrassment would go away.

The ideological force came from a vital front in the culture wars. After centuries of paying at least lip-service to religion, science started feeling its muscles. Science and religion moved ponderously into full combat mode. And the most crucial height to capture was that of human origins. Religion, or at least the Christian version, claimed that humans were the unique product of an all-powerful deity, and equipped (unlike animals) with immortal souls. The more science could show that humans were just another animal, the more religion's influence would be weakened.

All this was taking place during the heyday of genetic determinism, of Richard Dawkins's "selfish gene". Many saw genes as ruthless dictators, enforcing their irreversible wills on all forms of behavior as well as on physiology. And this was what led to behavioral scientists' big mistake.

Genes operate on behavior and physiology quite differently. On physiology, genes are indeed potent, determining how many limbs an organism will have, what kind they'll be, how big it will get, with relatively slight and slow-acting influence from the environment. Behavior is different. True, it's underpinned by genes, but genes don't determine it, except perhaps in the very simplest of organisms. Rather they make potentially available a wide range of behaviors (the more complex the species, the wider the range) from which the environment will select the most adaptive. It follows from this that while physiology is cumulative, behavior isn't.

The following will show you what I mean. Take a physiological organ like the eye, which started life as a cell that merely distinguished light from darkness, and then progressively acquired improvements such as depth perception and color discrimination (which also grew stepwise) until it achieved the sophistication of the human eye. In physiology, there's a cumulative effect as new bits and pieces are incorporated , and a ratchet effect that stops them from getting lost.

In behavior, there's neither. Take a behavior like communication. If behavior was like physiology, communication would have been like the eye. Relatively simple organisms would have had only a handful of signals. Signals would have increased in number as organisms grew more complex. Communication systems would have developed means for combining signals to give more complex messages, until they achieved the sophistication of human language. But the real picture is very different. Some fish have systems with as many signals as some primates. No system has even as many as a hundred signals. And in no system is any kind of meaningful combination possible. No cumulative effect, no ratchet.

But Hauser and most other behavioral scientists overlooked this difference. They saw language, like the eye, as resulting from the combination of many components, and in this they were right. But they thought that all or practically all of those components must, like the various stages of the eye, have pre-existed humans--that things like pattern recognition (indispensible for children acquiring the patterns of language) that Hauser claimed to find among cotton-top tamarins could not have originated anywhere but in the genomes of antecedent species. In other words, since every--or almost every--aspect of language had to have "precursors" of some kind in other species, biology's task was to go look for them.

But the assumptions on which this program was based weren't necessarily true, as recent developments in biology show. Evo-devo, the marriage of evolutionary and developmental biology, is revealing that genes are far from arbitrary dictators, that many are pluripotential and that interactions between genes, along with changes in the timing of regulatory genes and countless other factors (many of them epigenetic), can yield widely differing results. Niche construction theory is showing that animals can play a role in their own evolution. They can begin to practice new behaviors that go beyond what the animals were specifically programmed to do, and that become themselves selective pressures, altering genetic make-up to support the new behavior.

In light of this knowledge, a quite different explanation for the origins of human behavior becomes possible. Many of the things for which Hauser and his kind demand and seek "precursors" could have been produced practically from ground zero in a common-or-garden ape species whose lifestyle happened to demand something just a little extra. And this "little extra" could in turn have led to language, and language in turn could have triggered the cascade of changes leading to the cognitive and behavioral explosion that characterizes our species (for one account of such a process, see my latest book, Adam's Tongue).

In other words, Hauser fell victim to a soon-to-be-outdated view of evolution. He believed in that view, and, as the old adage has it, believing is seeing. When you're sure something must be there, you're liable to see it, whether it's really there or not, and at whatever the cost to your career.

He should have realized that "If it be maintained that certain powers, such as self-consciousness, abstraction etc., are peculiar to man, it may well be that these are the incidental results of other highly advanced intellectual faculties, and these again are mainly the result of the continued use of a highly developed language." No, I didn't say that. Darwin did--in 1871. It would take the science of the twenty-first century to show how and why he was right.
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